@kaia According to this article (Czech only, sorry), there should be an option for 50 more years. So we're safe :-)
The same article describes how Czechia has one lot permanently (if I read into it correctly) and that we are trying to exchange the two leased lots for another lot/s (there are too low bridges, so it is not very usable). The exchange could happen this year.
I didn't factcheck it, just remembered reading about this ~recently.